Poor melt strength of high density (HDPE) polyethylene appears to be one factor which makes it difficult to produce foamed articles therefrom. In the past, polyethylene foams have been made from high pressure-low density polyethylene; the high pressure-low density polyethylene exhibits relatively superior melt strength compared to that of the HDPE, at the same viscosities. The melt strength of HDPE can be increased simply by increasing the HDPE molecular weight; however, the increase in molecular weight is accompanied by increase in melt viscosity which interferes with processability and foamability.